1. The problem statement, all variables and given/known data A right circular cone with radius r and height h is being filled with water at the rate of 5 cu in./sec. How fast is the level of the water rising when the cone is half full. 2. Relevant equations V=r2h∏/3 3. The attempt at a solution V=5t. The level of the water is determined by h, so I need the find the derivative of h. h=15t/∏r2, but I'm pretty sure that's not right because r is not a constant, it depends on h. That's where I'm stuck.